Arbitration system limiting high priority successive grants

Abstract

Priority levels and bump values are assigned to requestors for access to a system resource. When access requests are received, arbitration of the requests is made in accordance with the assigned priorities, bump values, and the received access requests. If a high priority level access request is granted, then the same request will be held off for a successive number of requests as set by the bump values. In cases where the access is required for more than one request/grant cycle, the priority level access can be retained as long as required.

What is claimed is: 
     
       1. An access priority arbitration system comprising, in combination: means for assigning priority access levels;   means for setting bump values;   means for receiving a plurality of access requests;   means responsive to assigned priority access levels, access requests, and bump values for arbitrating the access request; and   means for controlling a mode of operation so that arbitration can be performed faster when a large number of access requests are anticipated.   
     
     
       2. The combination comprising: a plurality of request lines for supplying request signals indicative of requests for access to resources;   first means for assigning priority levels to each of said plurality of request lines;   second means for assigning a bump value to each of said plurality of request lines;   output means responsive to said first and second means and said request signals for supplying access grant signals to one of said plurality of request lines;   mode means for setting a mode of operation; and   means responsive to said mode means for causing said output to supply access grant signals at a different rate.